diff --git a/src/backend/utils/fmgr/dfmgr.c b/src/backend/utils/fmgr/dfmgr.c
index f41035d33c..6f70813a6d 100644
--- a/src/backend/utils/fmgr/dfmgr.c
+++ b/src/backend/utils/fmgr/dfmgr.c
@@ -300,14 +300,22 @@ incompatible_module_error(const char *libname,
 	 * block might not even have the fields we expect.
 	 */
 	if (magic_data.version != module_magic_data->version)
+	{
+		char		library_version[32];
+
+		if (module_magic_data->version >= 1000)
+			snprintf(library_version, sizeof(library_version), "%d",
+					 module_magic_data->version / 100);
+		else
+			snprintf(library_version, sizeof(library_version), "%d.%d",
+					 module_magic_data->version / 100,
+					 module_magic_data->version % 100);
 		ereport(ERROR,
 				(errmsg("incompatible library \"%s\": version mismatch",
 						libname),
-			  errdetail("Server is version %d.%d, library is version %d.%d.",
-						magic_data.version / 100,
-						magic_data.version % 100,
-						module_magic_data->version / 100,
-						module_magic_data->version % 100)));
+				 errdetail("Server is version %d, library is version %s.",
+						   magic_data.version / 100, library_version)));
+	}
 
 	/*
 	 * Otherwise, spell out which fields don't agree.
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 9c0af4e848..4aaf657cce 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -635,8 +635,11 @@ exec_command(const char *cmd,
 
 		if (pset.sversion < 80400)
 		{
-			psql_error("The server (version %d.%d) does not support editing function source.\n",
-					   pset.sversion / 10000, (pset.sversion / 100) % 100);
+			char		sverbuf[32];
+
+			psql_error("The server (version %s) does not support editing function source.\n",
+					   formatPGVersionNumber(pset.sversion, false,
+											 sverbuf, sizeof(sverbuf)));
 			status = PSQL_CMD_ERROR;
 		}
 		else if (!query_buf)
@@ -731,8 +734,11 @@ exec_command(const char *cmd,
 
 		if (pset.sversion < 70400)
 		{
-			psql_error("The server (version %d.%d) does not support editing view definitions.\n",
-					   pset.sversion / 10000, (pset.sversion / 100) % 100);
+			char		sverbuf[32];
+
+			psql_error("The server (version %s) does not support editing view definitions.\n",
+					   formatPGVersionNumber(pset.sversion, false,
+											 sverbuf, sizeof(sverbuf)));
 			status = PSQL_CMD_ERROR;
 		}
 		else if (!query_buf)
@@ -1362,8 +1368,11 @@ exec_command(const char *cmd,
 									  OT_WHOLE_LINE, NULL, true);
 		if (pset.sversion < 80400)
 		{
-			psql_error("The server (version %d.%d) does not support showing function source.\n",
-					   pset.sversion / 10000, (pset.sversion / 100) % 100);
+			char		sverbuf[32];
+
+			psql_error("The server (version %s) does not support showing function source.\n",
+					   formatPGVersionNumber(pset.sversion, false,
+											 sverbuf, sizeof(sverbuf)));
 			status = PSQL_CMD_ERROR;
 		}
 		else if (!func)
@@ -1441,8 +1450,11 @@ exec_command(const char *cmd,
 									  OT_WHOLE_LINE, NULL, true);
 		if (pset.sversion < 70400)
 		{
-			psql_error("The server (version %d.%d) does not support showing view definitions.\n",
-					   pset.sversion / 10000, (pset.sversion / 100) % 100);
+			char		sverbuf[32];
+
+			psql_error("The server (version %s) does not support showing view definitions.\n",
+					   formatPGVersionNumber(pset.sversion, false,
+											 sverbuf, sizeof(sverbuf)));
 			status = PSQL_CMD_ERROR;
 		}
 		else if (!view)
@@ -2014,22 +2026,21 @@ connection_warnings(bool in_startup)
 	if (!pset.quiet && !pset.notty)
 	{
 		int			client_ver = PG_VERSION_NUM;
+		char		cverbuf[32];
+		char		sverbuf[32];
 
 		if (pset.sversion != client_ver)
 		{
 			const char *server_version;
-			char		server_ver_str[16];
 
 			/* Try to get full text form, might include "devel" etc */
 			server_version = PQparameterStatus(pset.db, "server_version");
+			/* Otherwise fall back on pset.sversion */
 			if (!server_version)
 			{
-				snprintf(server_ver_str, sizeof(server_ver_str),
-						 "%d.%d.%d",
-						 pset.sversion / 10000,
-						 (pset.sversion / 100) % 100,
-						 pset.sversion % 100);
-				server_version = server_ver_str;
+				formatPGVersionNumber(pset.sversion, true,
+									  sverbuf, sizeof(sverbuf));
+				server_version = sverbuf;
 			}
 
 			printf(_("%s (%s, server %s)\n"),
@@ -2040,10 +2051,13 @@ connection_warnings(bool in_startup)
 			printf("%s (%s)\n", pset.progname, PG_VERSION);
 
 		if (pset.sversion / 100 > client_ver / 100)
-			printf(_("WARNING: %s major version %d.%d, server major version %d.%d.\n"
+			printf(_("WARNING: %s major version %s, server major version %s.\n"
 					 "         Some psql features might not work.\n"),
-				 pset.progname, client_ver / 10000, (client_ver / 100) % 100,
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+				   pset.progname,
+				   formatPGVersionNumber(client_ver, false,
+										 cverbuf, sizeof(cverbuf)),
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 
 #ifdef WIN32
 		checkWin32Codepage();
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 2450b9c3f8..7399950284 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -18,6 +18,7 @@
 #include <win32.h>
 #endif
 
+#include "fe_utils/string_utils.h"
 #include "portability/instr_time.h"
 
 #include "settings.h"
@@ -1202,8 +1203,11 @@ SendQuery(const char *query)
 	{
 		if (on_error_rollback_warning == false && pset.sversion < 80000)
 		{
-			psql_error("The server (version %d.%d) does not support savepoints for ON_ERROR_ROLLBACK.\n",
-					   pset.sversion / 10000, (pset.sversion / 100) % 100);
+			char		sverbuf[32];
+
+			psql_error("The server (version %s) does not support savepoints for ON_ERROR_ROLLBACK.\n",
+					   formatPGVersionNumber(pset.sversion, false,
+											 sverbuf, sizeof(sverbuf)));
 			on_error_rollback_warning = true;
 		}
 		else
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 27be10215b..6275a688c7 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -142,8 +142,11 @@ describeAccessMethods(const char *pattern, bool verbose)
 
 	if (pset.sversion < 90600)
 	{
-		psql_error("The server (version %d.%d) does not support access methods.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support access methods.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -205,8 +208,11 @@ describeTablespaces(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80000)
 	{
-		psql_error("The server (version %d.%d) does not support tablespaces.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support tablespaces.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -311,8 +317,11 @@ describeFunctions(const char *functypes, const char *pattern, bool verbose, bool
 
 	if (showWindow && pset.sversion < 80400)
 	{
-		psql_error("\\df does not take a \"w\" option with server version %d.%d\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("\\df does not take a \"w\" option with server version %s\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -962,8 +971,11 @@ listDefaultACLs(const char *pattern)
 
 	if (pset.sversion < 90000)
 	{
-		psql_error("The server (version %d.%d) does not support altering default privileges.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support altering default privileges.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -3548,8 +3560,11 @@ listCollations(const char *pattern, bool verbose, bool showSystem)
 
 	if (pset.sversion < 90100)
 	{
-		psql_error("The server (version %d.%d) does not support collations.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support collations.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -3680,8 +3695,11 @@ listTSParsers(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80300)
 	{
-		psql_error("The server (version %d.%d) does not support full text search.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support full text search.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -3915,8 +3933,11 @@ listTSDictionaries(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80300)
 	{
-		psql_error("The server (version %d.%d) does not support full text search.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support full text search.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -3983,8 +4004,11 @@ listTSTemplates(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80300)
 	{
-		psql_error("The server (version %d.%d) does not support full text search.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support full text search.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4051,8 +4075,11 @@ listTSConfigs(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80300)
 	{
-		psql_error("The server (version %d.%d) does not support full text search.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support full text search.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4249,8 +4276,11 @@ listForeignDataWrappers(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80400)
 	{
-		psql_error("The server (version %d.%d) does not support foreign-data wrappers.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support foreign-data wrappers.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4329,8 +4359,11 @@ listForeignServers(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80400)
 	{
-		psql_error("The server (version %d.%d) does not support foreign servers.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support foreign servers.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4408,8 +4441,11 @@ listUserMappings(const char *pattern, bool verbose)
 
 	if (pset.sversion < 80400)
 	{
-		psql_error("The server (version %d.%d) does not support user mappings.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support user mappings.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4466,8 +4502,11 @@ listForeignTables(const char *pattern, bool verbose)
 
 	if (pset.sversion < 90100)
 	{
-		psql_error("The server (version %d.%d) does not support foreign tables.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support foreign tables.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4541,8 +4580,11 @@ listExtensions(const char *pattern)
 
 	if (pset.sversion < 90100)
 	{
-		psql_error("The server (version %d.%d) does not support extensions.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support extensions.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
@@ -4595,8 +4637,11 @@ listExtensionContents(const char *pattern)
 
 	if (pset.sversion < 90100)
 	{
-		psql_error("The server (version %d.%d) does not support extensions.\n",
-				   pset.sversion / 10000, (pset.sversion / 100) % 100);
+		char		sverbuf[32];
+
+		psql_error("The server (version %s) does not support extensions.\n",
+				   formatPGVersionNumber(pset.sversion, false,
+										 sverbuf, sizeof(sverbuf)));
 		return true;
 	}
 
diff --git a/src/fe_utils/string_utils.c b/src/fe_utils/string_utils.c
index f986dbcf39..2c566b1ad7 100644
--- a/src/fe_utils/string_utils.c
+++ b/src/fe_utils/string_utils.c
@@ -168,6 +168,44 @@ fmtQualifiedId(int remoteVersion, const char *schema, const char *id)
 }
 
 
+/*
+ * Format a Postgres version number (in the PG_VERSION_NUM integer format
+ * returned by PQserverVersion()) as a string.  This exists mainly to
+ * encapsulate knowledge about two-part vs. three-part version numbers.
+ *
+ * For re-entrancy, caller must supply the buffer the string is put in.
+ * Recommended size of the buffer is 32 bytes.
+ *
+ * Returns address of 'buf', as a notational convenience.
+ */
+char *
+formatPGVersionNumber(int version_number, bool include_minor,
+					  char *buf, size_t buflen)
+{
+	if (version_number >= 100000)
+	{
+		/* New two-part style */
+		if (include_minor)
+			snprintf(buf, buflen, "%d.%d", version_number / 10000,
+					 version_number % 10000);
+		else
+			snprintf(buf, buflen, "%d", version_number / 10000);
+	}
+	else
+	{
+		/* Old three-part style */
+		if (include_minor)
+			snprintf(buf, buflen, "%d.%d.%d", version_number / 10000,
+					 (version_number / 100) % 100,
+					 version_number % 100);
+		else
+			snprintf(buf, buflen, "%d.%d", version_number / 10000,
+					 (version_number / 100) % 100);
+	}
+	return buf;
+}
+
+
 /*
  * Convert a string value to an SQL string literal and append it to
  * the given buffer.  We assume the specified client_encoding and
diff --git a/src/include/fe_utils/string_utils.h b/src/include/fe_utils/string_utils.h
index 7bbed360a3..452ffc0771 100644
--- a/src/include/fe_utils/string_utils.h
+++ b/src/include/fe_utils/string_utils.h
@@ -30,6 +30,9 @@ extern const char *fmtId(const char *identifier);
 extern const char *fmtQualifiedId(int remoteVersion,
 			   const char *schema, const char *id);
 
+extern char *formatPGVersionNumber(int version_number, bool include_minor,
+					  char *buf, size_t buflen);
+
 extern void appendStringLiteral(PQExpBuffer buf, const char *str,
 					int encoding, bool std_strings);
 extern void appendStringLiteralConn(PQExpBuffer buf, const char *str,