diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index fbd834b..10f6299 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -715,7 +715,7 @@
 		}
 
 		/* Check "version" K/V item */
-		if (!memcmp(str, VERSION_KEY, sz)) {
+		if (sz >= strlen(VERSION_KEY) && !memcmp(str, VERSION_KEY, strlen(VERSION_KEY))) {
 			int i, type = *p++;
 
 			/* The value must be a string */
@@ -744,7 +744,7 @@
 			}
 		}
 		/* Check "max-frame-size" K/V item */
-		else if (!memcmp(str, MAX_FRAME_SIZE_KEY, sz)) {
+		else if (sz >= strlen(MAX_FRAME_SIZE_KEY) && !memcmp(str, MAX_FRAME_SIZE_KEY, strlen(MAX_FRAME_SIZE_KEY))) {
 			int type = *p++;
 
 			/* The value must be integer */
@@ -767,7 +767,7 @@
 			max_frame_size = sz;
 		}
 		/* Check "capabilities" K/V item */
-		else if (!memcmp(str, CAPABILITIES_KEY, sz)) {
+		else if (sz >= strlen(CAPABILITIES_KEY) && !memcmp(str, CAPABILITIES_KEY, strlen(CAPABILITIES_KEY))) {
 			int type = *p++;
 
 			/* The value must be a string */
@@ -901,7 +901,7 @@
 		}
 
 		/* Check "status-code" K/V item */
-		if (!memcmp(str, STATUS_CODE_KEY, sz)) {
+		if (sz >= strlen(STATUS_CODE_KEY) && !memcmp(str, STATUS_CODE_KEY, strlen(STATUS_CODE_KEY))) {
 			int type = *p++;
 
 			/* The value must be an integer */
@@ -920,7 +920,7 @@
 		}
 
 		/* Check "message" K/V item */
-		else if (!memcmp(str, MSG_KEY, sz)) {
+		else if (sz >= strlen(MSG_KEY) && !memcmp(str, MSG_KEY, strlen(MSG_KEY))) {
 			int type = *p++;
 
 			/* The value must be a string */