diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index c1a9ea430..61c4a25b2 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -343,7 +343,7 @@ capable of storing values in the range
 .BR INTMAX_MAX ].
 .PP
 The macro
-.B INTMAX_C
+.BR INTMAX_C ()
 .\" TODO: Document INT*_C(3)
 expands its argument to an integer constant of type
 .IR intmax_t .
@@ -1269,7 +1269,7 @@ capable of storing values in the range [0,
 .BR UINTMAX_MAX ].
 .PP
 The macro
-.B UINTMAX_C
+.BR UINTMAX_C ()
 .\" TODO: Document UINT*_C(3)
 expands its argument to an integer constant of type
 .IR uintmax_t .