diff --git a/configure b/configure
index 8cbc95fe11..b8fc00b1eb 100755
--- a/configure
+++ b/configure
@@ -855,7 +855,7 @@ Optional Packages:
   --with-libraries=DIRS   look for additional libraries in DIRS
   --with-libs=DIRS        alternative spelling of --with-libraries
   --with-pgport=PORTNUM   change default port number 5432
-  --with-threads          allow libpq to be thread-safe
+  --with-threads          allow libpq and ecpg to be thread-safe
   --with-tcl              build Tcl and Tk interfaces
   --without-tk            do not build Tk interfaces if Tcl is enabled
   --with-tclconfig=DIR    tclConfig.sh and tkConfig.sh are in DIR
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6e8cac0e99..5a3e62915f 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -588,7 +588,7 @@
 /* Define to select SysV-style shared memory. */
 #undef USE_SYSV_SHARED_MEMORY
 
-/* Define to 1 to build libpq with threads. (--with-threads) */
+/* Define to 1 to build libpq and ecpg to be thread-safe. (--with-threads) */
 #undef USE_THREADS
 
 /* Define to select unnamed POSIX semaphores. */