diff --git a/nasm.h b/nasm.h
index 7ff19027..cbd9462f 100644
--- a/nasm.h
+++ b/nasm.h
@@ -421,6 +421,12 @@ enum {
 /* Register names automatically generated from regs.dat */
 #include "regs.h"
 
+/* verify value to be register */
+static inline int is_register(int reg)
+{
+    return reg >= EXPR_REG_START && reg < REG_ENUM_LIMIT;
+}
+
 enum ccode {			/* condition code names */
     C_A, C_AE, C_B, C_BE, C_C, C_E, C_G, C_GE, C_L, C_LE, C_NA, C_NAE,
     C_NB, C_NBE, C_NC, C_NE, C_NG, C_NGE, C_NL, C_NLE, C_NO, C_NP,
diff --git a/regs.pl b/regs.pl
index e6350f92..82c48295 100755
--- a/regs.pl
+++ b/regs.pl
@@ -134,13 +134,6 @@ if ( $fmt eq 'h' ) {
     foreach $reg ( sort(keys(%regs)) ) {
 	printf "#define %-15s %2d\n", "REG_NUM_\U${reg}", $regvals{$reg};
     }
-
-    print "\n";
-    print "static inline int is_register(int reg)\n";
-    print "{\n";
-    print "    return reg >= EXPR_REG_START && reg < REG_ENUM_LIMIT;\n";
-    print "}\n";
-
     print "\n\n#endif /* NASM_REGS_H */\n";
 } elsif ( $fmt eq 'c' ) {
     # Output regs.c