diff --git a/src/halfvec.c b/src/halfvec.c
index 015bf48..c7bc077 100644
--- a/src/halfvec.c
+++ b/src/halfvec.c
@@ -198,8 +198,9 @@ halfvec_in(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 					 errmsg("invalid input syntax for type halfvec: \"%s\"", lit)));
 
-		/* Use strtof like float4in to avoid a double-rounding problem */
 		errno = 0;
+
+		/* Postgres sets LC_NUMERIC to C on startup */
 		val = strtof(pt, &stringEnd);
 
 		if (stringEnd == pt)
diff --git a/src/sparsevec.c b/src/sparsevec.c
index ca6a878..ac7e792 100644
--- a/src/sparsevec.c
+++ b/src/sparsevec.c
@@ -268,8 +268,11 @@ sparsevec_in(PG_FUNCTION_ARGS)
 		while (sparsevec_isspace(*stringEnd))
 			stringEnd++;
 
-		errno = 0;
 		pt = stringEnd;
+		errno = 0;
+
+		/* Use strtof like float4in to avoid a double-rounding problem */
+		/* Postgres sets LC_NUMERIC to C on startup */
 		value = strtof(pt, &stringEnd);
 
 		if (stringEnd == pt)
diff --git a/src/vector.c b/src/vector.c
index b029f85..51189fc 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -222,8 +222,10 @@ vector_in(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 					 errmsg("invalid input syntax for type vector: \"%s\"", lit)));
 
-		/* Use strtof like float4in to avoid a double-rounding problem */
 		errno = 0;
+
+		/* Use strtof like float4in to avoid a double-rounding problem */
+		/* Postgres sets LC_NUMERIC to C on startup */
 		val = strtof(pt, &stringEnd);
 
 		if (stringEnd == pt)