diff --git a/src/char_ref.c b/src/char_ref.c
index e693e04..bb4a177 100644
--- a/src/char_ref.c
+++ b/src/char_ref.c
@@ -23037,7 +23037,7 @@ static bool consume_named_ref(
   if (cs >= 7623) {
     assert(output->first != kGumboNoChar);
     char last_char = *(te - 1);
-    int len = te - start;
+    int len = (int) (te - start);
     if (last_char == ';') {
       bool matched = utf8iterator_maybe_consume_match(input, start, len, true);
       assert(matched);
diff --git a/src/error.c b/src/error.c
index 6b884ca..12da28b 100644
--- a/src/error.c
+++ b/src/error.c
@@ -34,7 +34,7 @@
 // written.
 static int print_message(GumboStringBuffer* output, const char* format, ...) {
   va_list args;
-  int remaining_capacity = output->capacity - output->length;
+  unsigned int remaining_capacity = (unsigned int) (output->capacity - output->length);
   va_start(args, format);
   int bytes_written = vsnprintf(output->data + output->length,
                                 remaining_capacity, format, args);
@@ -61,9 +61,9 @@ static int print_message(GumboStringBuffer* output, const char* format, ...) {
   }
 #endif
 
-  if (bytes_written >= remaining_capacity) {
+  if (bytes_written >= (int) remaining_capacity) {
     gumbo_string_buffer_reserve(output->capacity + bytes_written, output);
-    remaining_capacity = output->capacity - output->length;
+    remaining_capacity = (unsigned int) (output->capacity - output->length);
     va_start(args, format);
     bytes_written = vsnprintf(output->data + output->length,
                               remaining_capacity, format, args);
@@ -79,7 +79,8 @@ static void print_tag_stack(const GumboParserError* error, GumboStringBuffer* ou
     if (i) {
       print_message(output, ", ");
     }
-    GumboTag tag = (GumboTag) error->tag_stack.data[i];
+    // cast to uintptr_t first to prevent void ptr to enum cast warning
+    GumboTag tag = (GumboTag)( (uintptr_t) (error->tag_stack.data[i]) );
     print_message(output, gumbo_normalized_tagname(tag));
   }
   gumbo_string_buffer_append_codepoint('.', output);
diff --git a/src/gumbo.h b/src/gumbo.h
index a63bd91..b579c85 100644
--- a/src/gumbo.h
+++ b/src/gumbo.h
@@ -205,7 +205,7 @@ const char* gumbo_normalize_svg_tagname(const GumboStringPiece* tagname);
  * enum. The `tag` version expects `tagname` to be NULL-terminated
  */
 GumboTag gumbo_tag_enum(const char* tagname);
-GumboTag gumbo_tagn_enum(const char* tagname, int length);
+GumboTag gumbo_tagn_enum(const char* tagname, unsigned int length);
 
 /**
  * Attribute namespaces.
diff --git a/src/gumbo_edit.c b/src/gumbo_edit.c
index 9bf369f..2d4dde0 100644
--- a/src/gumbo_edit.c
+++ b/src/gumbo_edit.c
@@ -167,7 +167,7 @@ void gumbo_insert_node(GumboNode* node, GumboNode* target_parent, int target_ind
       assert(0);
     }
     assert(index >= 0);
-    assert(index < children->length);
+    assert(index <= children->length);
     node->parent = parent;
     node->index_within_parent = index;
     gumbo_vector_insert_at((void*) node, index, children);
diff --git a/src/parser.c b/src/parser.c
index 2ea5d28..1b3d1ea 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -624,7 +624,8 @@ static GumboInsertionMode get_current_template_insertion_mode(const GumboParser*
   if (template_insertion_modes->length == 0) {
     return GUMBO_INSERTION_MODE_INITIAL;
   }
-  return (GumboInsertionMode) template_insertion_modes->data[(template_insertion_modes->length - 1)];
+  // cast to a uintptr_t first to prevent void ptr to enum warning
+  return (GumboInsertionMode) ( (uintptr_t) (template_insertion_modes->data[(template_insertion_modes->length - 1)] ) );
 }
 
 // http://www.whatwg.org/specs/web-apps/current-work/multipage/tree-construction.html#mathml-text-integration-point
diff --git a/src/tag.c b/src/tag.c
index 3a5dd2e..2da56ed 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -87,9 +87,9 @@ static int case_memcmp(const char* s1, const char* s2, unsigned int n) {
   return 0;
 }
 
-GumboTag gumbo_tagn_enum(const char* tagname, int length) {
+GumboTag gumbo_tagn_enum(const char* tagname, unsigned int length) {
   if (length) {
-    unsigned int key = tag_hash(tagname, length);
+      unsigned int key = tag_hash(tagname, length);
     if (key < TAG_MAP_SIZE) {
       GumboTag tag = kGumboTagMap[key];
       if (length == kGumboTagSizes[(int) tag] &&
@@ -101,5 +101,5 @@ GumboTag gumbo_tagn_enum(const char* tagname, int length) {
 }
 
 GumboTag gumbo_tag_enum(const char* tagname) {
-  return gumbo_tagn_enum(tagname, strlen(tagname));
+    return gumbo_tagn_enum(tagname, (unsigned int) strlen(tagname));
 }
diff --git a/src/tokenizer.c b/src/tokenizer.c
index 385a34f..6b9f0bd 100644
--- a/src/tokenizer.c
+++ b/src/tokenizer.c
@@ -742,7 +742,7 @@ static void finish_tag_name(GumboParser* parser) {
   GumboTagState* tag_state = &tokenizer->_tag_state;
 
   tag_state->_tag = gumbo_tagn_enum(
-		tag_state->_buffer.data, tag_state->_buffer.length);
+                                    tag_state->_buffer.data, (unsigned int) (tag_state->_buffer.length));
   reinitialize_tag_buffer(parser);
 }
 
@@ -831,7 +831,7 @@ static bool is_appropriate_end_tag(GumboParser* parser) {
   assert(!tag_state->_is_start_tag);
   return tag_state->_last_start_tag != GUMBO_TAG_LAST &&
       tag_state->_last_start_tag ==
-	  gumbo_tagn_enum(tag_state->_buffer.data, tag_state->_buffer.length);
+	  gumbo_tagn_enum(tag_state->_buffer.data, (unsigned int) (tag_state->_buffer.length));
 }
 
 void gumbo_tokenizer_state_init(
diff --git a/src/vector.c b/src/vector.c
index 9e3ae66..36178d6 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -29,7 +29,7 @@ const GumboVector kGumboEmptyVector = { NULL, 0, 0 };
 
 void gumbo_vector_init(size_t initial_capacity, GumboVector* vector) {
   vector->length = 0;
-  vector->capacity = initial_capacity;
+  vector->capacity = (unsigned int) initial_capacity;
   vector->data = NULL;
   if (initial_capacity)
     vector->data = gumbo_malloc(sizeof(void*) * initial_capacity);