diff --git a/src/decode-icmpv4.c b/src/decode-icmpv4.c
index 43c1e80663..07c53dbc22 100644
--- a/src/decode-icmpv4.c
+++ b/src/decode-icmpv4.c
@@ -12,58 +12,6 @@
 #include "util-unittest.h"
 #include "util-debug.h"
 
-/**
- * \brief Calculates the checksum for the ICMP packet
- *
- * \param pkt  Pointer to the start of the ICMP packet
- * \param hlen Total length of the ICMP packet(header + payload)
- *
- * \retval csum Checksum for the ICMP packet
- */
-inline uint16_t ICMPV4CalculateChecksum(uint16_t *pkt, uint16_t tlen)
-{
-    uint16_t pad = 0;
-    uint32_t csum = pkt[0];
-
-    tlen -= 4;
-    pkt += 2;
-
-    while (tlen >= 32) {
-        csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5] + pkt[6] +
-            pkt[7] + pkt[8] + pkt[9] + pkt[10] + pkt[11] + pkt[12] + pkt[13] +
-            pkt[14] + pkt[15];
-        tlen -= 32;
-        pkt += 16;
-    }
-
-    while(tlen >= 8) {
-        csum += pkt[0] + pkt[1] + pkt[2] + pkt[3];
-        tlen -= 8;
-        pkt += 4;
-    }
-
-    while(tlen >= 4) {
-        csum += pkt[0] + pkt[1];
-        tlen -= 4;
-        pkt += 2;
-    }
-
-    while (tlen > 1) {
-        csum += pkt[0];
-        tlen -= 2;
-        pkt += 1;
-    }
-
-    if (tlen == 1) {
-        *(uint8_t *)(&pad) = (*(uint8_t *)pkt);
-        csum += pad;
-    }
-
-    csum = (csum >> 16) + (csum & 0x0000FFFF);
-
-    return (uint16_t) ~csum;
-}
-
 /**
  * Note, this is the IP header, plus a bit of the original packet, not the whole thing!
  */
diff --git a/src/decode-icmpv4.h b/src/decode-icmpv4.h
index 2b92d9713b..f72f557edc 100644
--- a/src/decode-icmpv4.h
+++ b/src/decode-icmpv4.h
@@ -222,9 +222,62 @@ typedef struct ICMPV4Cache_ {
     int32_t comp_csum;
 } ICMPV4Cache;
 
-inline uint16_t ICMPV4CalculateChecksum(uint16_t *, uint16_t);
-
 void DecodeICMPV4RegisterTests(void);
 
+/** ------ Inline functions ------ */
+static inline uint16_t ICMPV4CalculateChecksum(uint16_t *, uint16_t);
+
+/**
+ * \brief Calculates the checksum for the ICMP packet
+ *
+ * \param pkt  Pointer to the start of the ICMP packet
+ * \param hlen Total length of the ICMP packet(header + payload)
+ *
+ * \retval csum Checksum for the ICMP packet
+ */
+static inline uint16_t ICMPV4CalculateChecksum(uint16_t *pkt, uint16_t tlen)
+{
+    uint16_t pad = 0;
+    uint32_t csum = pkt[0];
+
+    tlen -= 4;
+    pkt += 2;
+
+    while (tlen >= 32) {
+        csum += pkt[0] + pkt[1] + pkt[2] + pkt[3] + pkt[4] + pkt[5] + pkt[6] +
+            pkt[7] + pkt[8] + pkt[9] + pkt[10] + pkt[11] + pkt[12] + pkt[13] +
+            pkt[14] + pkt[15];
+        tlen -= 32;
+        pkt += 16;
+    }
+
+    while(tlen >= 8) {
+        csum += pkt[0] + pkt[1] + pkt[2] + pkt[3];
+        tlen -= 8;
+        pkt += 4;
+    }
+
+    while(tlen >= 4) {
+        csum += pkt[0] + pkt[1];
+        tlen -= 4;
+        pkt += 2;
+    }
+
+    while (tlen > 1) {
+        csum += pkt[0];
+        tlen -= 2;
+        pkt += 1;
+    }
+
+    if (tlen == 1) {
+        *(uint8_t *)(&pad) = (*(uint8_t *)pkt);
+        csum += pad;
+    }
+
+    csum = (csum >> 16) + (csum & 0x0000FFFF);
+
+    return (uint16_t) ~csum;
+}
+
 #endif /* __DECODE_ICMPV4_H__ */