diff --git a/hw/xfree86/parser/Configint.h b/hw/xfree86/parser/Configint.h
index 001b3a5ed0..d42a4fd0e7 100644
--- a/hw/xfree86/parser/Configint.h
+++ b/hw/xfree86/parser/Configint.h
@@ -203,6 +203,8 @@ else\
 "The number \"%d\" given in this section must be in octal (0xxx) format."
 #define GPU_DEVICE_TOO_MANY \
 "More than %d GPU devices defined."
+#define CLOCKS_TOO_MANY \
+"More than %d Clocks defined."
 
 /* Warning messages */
 #define OBSOLETE_MSG \
diff --git a/hw/xfree86/parser/Device.c b/hw/xfree86/parser/Device.c
index 383f4727e8..3e1ed3bf7b 100644
--- a/hw/xfree86/parser/Device.c
+++ b/hw/xfree86/parser/Device.c
@@ -206,6 +206,8 @@ xf86parseDeviceSection(void)
                 ptr->dev_clock[i] = (int) (xf86_lex_val.realnum * 1000.0 + 0.5);
                 token = xf86getSubToken(&(ptr->dev_comment));
             }
+            if (token == NUMBER && i >= CONF_MAXCLOCKS)
+                Error(CLOCKS_TOO_MANY, CONF_MAXCLOCKS);
             ptr->dev_clocks = i;
             xf86unGetToken(token);
             break;