diff --git a/src/nfa/castlecompile.cpp b/src/nfa/castlecompile.cpp
index 67d9b3d4..5e8b662a 100644
--- a/src/nfa/castlecompile.cpp
+++ b/src/nfa/castlecompile.cpp
@@ -205,7 +205,7 @@ bool graph_empty(const Graph &g) {
 static
 vector<u32> removeClique(CliqueGraph &cg) {
     vector<vector<u32>> cliquesVec(1);
-    DEBUG_PRINTF("graph size:%lu\n", num_vertices(cg));
+    DEBUG_PRINTF("graph size:%zu\n", num_vertices(cg));
     findCliqueGroup(cg, cliquesVec[0]);
     while (!graph_empty(cg)) {
         const vector<u32> &c = cliquesVec.back();
@@ -237,7 +237,7 @@ vector<u32> removeClique(CliqueGraph &cg) {
         }
     }
 
-    DEBUG_PRINTF("clique size:%lu\n", cliquesVec[id].size());
+    DEBUG_PRINTF("clique size:%zu\n", cliquesVec[id].size());
     return cliquesVec[id];
 }
 
@@ -315,7 +315,7 @@ vector<vector<u32>> checkExclusion(u32 &streamStateSize,
 
         lower += CLIQUE_GRAPH_MAX_SIZE;
     }
-    DEBUG_PRINTF("clique size %lu, num of repeats %lu\n",
+    DEBUG_PRINTF("clique size %zu, num of repeats %zu\n",
                  total, numRepeats);
     if (total == numRepeats) {
         exclusive = PURE_EXCLUSIVE;
diff --git a/src/nfagraph/ng_equivalence.cpp b/src/nfagraph/ng_equivalence.cpp
index 148cad49..b8e5a8d6 100644
--- a/src/nfagraph/ng_equivalence.cpp
+++ b/src/nfagraph/ng_equivalence.cpp
@@ -377,7 +377,7 @@ void partitionGraph(ptr_vector<VertexInfo> &infos, ClassMap &classes,
             work_queue.push(eq_class);
         }
     }
-    DEBUG_PRINTF("partitioned, %lu equivalence classes\n", classinfomap.size());
+    DEBUG_PRINTF("partitioned, %zu equivalence classes\n", classinfomap.size());
 }
 
 // generalized equivalence processing (left and right)