diff --git a/man3/resolver.3 b/man3/resolver.3
index 54c5d2f7e..ea22acc47 100644
--- a/man3/resolver.3
+++ b/man3/resolver.3
@@ -377,7 +377,7 @@ Do not strip TSIG records.
 This option was present but unimplemented in glibc until version 2.24;
 since glibc 2.25, it is deprecated, and its usage produces a warning.
 .TP
-.B RES_BLAST " (unimplemented; deprecated in glibc 2.25)"
+.BR RES_BLAST " (unimplemented; deprecated in glibc 2.25)"
 Send each query simultaneously and recursively to all servers.
 This option was present but unimplemented in glibc until version 2.24;
 since glibc 2.25, it is deprecated, and its usage produces a warning.