diff --git a/Ibm1130/ibm1130_defs.h b/Ibm1130/ibm1130_defs.h
index d4f925b3..c25e2153 100644
--- a/Ibm1130/ibm1130_defs.h
+++ b/Ibm1130/ibm1130_defs.h
@@ -27,7 +27,7 @@
 #define MAX(a,b)  (((a) >= (b)) ? (a) : (b))
 
 #ifndef _WIN32
-   int strnicmp (const char *a, const char *b, int n);
+   int strnicmp (const char *a, const char *b, size_t n);
    int strcmpi  (const char *a, const char *b);
 #endif
 
diff --git a/Ibm1130/ibm1130_sys.c b/Ibm1130/ibm1130_sys.c
index 22cce803..1b3fb86d 100644
--- a/Ibm1130/ibm1130_sys.c
+++ b/Ibm1130/ibm1130_sys.c
@@ -455,7 +455,7 @@ t_stat parse_sym (char *cptr, t_addr addr, UNIT *uptr, t_value *val, int32 sw)
 
 #ifndef _WIN32
 
-int strnicmp (const char *a, const char *b, int n)
+int strnicmp (const char *a, const char *b, size_t n)
 {
 	int ca, cb;