diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c
index ee6c4795f1..a85dfdfec4 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -73,6 +73,7 @@
 #include "utils/builtins.h"
 #include "utils/date.h"
 #include "utils/datum.h"
+#include "utils/float.h"
 #include "utils/inet.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
@@ -1872,6 +1873,14 @@ brin_minmax_multi_distance_float4(PG_FUNCTION_ARGS)
 	float		a1 = PG_GETARG_FLOAT4(0);
 	float		a2 = PG_GETARG_FLOAT4(1);
 
+	/* if both values are NaN, then we consider them the same */
+	if (isnan(a1) && isnan(a2))
+		PG_RETURN_FLOAT8(0.0);
+
+	/* if one value is NaN, use infinite distance */
+	if (isnan(a1) || isnan(a2))
+		PG_RETURN_FLOAT8(get_float8_infinity());
+
 	/*
 	 * We know the values are range boundaries, but the range may be collapsed
 	 * (i.e. single points), with equal values.
@@ -1890,6 +1899,14 @@ brin_minmax_multi_distance_float8(PG_FUNCTION_ARGS)
 	double		a1 = PG_GETARG_FLOAT8(0);
 	double		a2 = PG_GETARG_FLOAT8(1);
 
+	/* if both values are NaN, then we consider them the same */
+	if (isnan(a1) && isnan(a2))
+		PG_RETURN_FLOAT8(0.0);
+
+	/* if one value is NaN, use infinite distance */
+	if (isnan(a1) || isnan(a2))
+		PG_RETURN_FLOAT8(get_float8_infinity());
+
 	/*
 	 * We know the values are range boundaries, but the range may be collapsed
 	 * (i.e. single points), with equal values.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index d3d693e464..f3309f433f 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -347,6 +347,9 @@ SELECT brin_desummarize_range('brinidx_multi', 0);
 (1 row)
 
 VACUUM brintest_multi;  -- force a summarization cycle in brinidx
+-- Try inserting a values with NaN, to test distance calculation.
+insert into public.brintest_multi (float4col) values (real 'nan');
+insert into public.brintest_multi (float8col) values (real 'nan');
 UPDATE brintest_multi SET int8col = int8col * int4col;
 -- Tests for brin_summarize_new_values
 SELECT brin_summarize_new_values('brintest_multi'); -- error, not an index
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index 70b751068b..2189b6ccf4 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -351,6 +351,10 @@ FROM tenk1 ORDER BY unique2 LIMIT 5 OFFSET 5;
 SELECT brin_desummarize_range('brinidx_multi', 0);
 VACUUM brintest_multi;  -- force a summarization cycle in brinidx
 
+-- Try inserting a values with NaN, to test distance calculation.
+insert into public.brintest_multi (float4col) values (real 'nan');
+insert into public.brintest_multi (float8col) values (real 'nan');
+
 UPDATE brintest_multi SET int8col = int8col * int4col;
 
 -- Tests for brin_summarize_new_values