diff --git a/libs/dfi/gtest/src/dyn_type_tests.cpp b/libs/dfi/gtest/src/dyn_type_tests.cpp
index f3cb50790..cd7e266a4 100644
--- a/libs/dfi/gtest/src/dyn_type_tests.cpp
+++ b/libs/dfi/gtest/src/dyn_type_tests.cpp
@@ -268,6 +268,7 @@ TEST_F(DynTypeTests, SequenceWithPointerTest) {
     ASSERT_EQ(0, rc);
     ASSERT_TRUE(seq != NULL);
 
+    dynType_sequence_init(type, seq);
     rc = dynType_sequence_alloc(type, seq, 1);
     ASSERT_EQ(0, rc);
     struct item **loc = NULL;
@@ -341,6 +342,53 @@ TEST_F(DynTypeTests, SequenceReserve) {
     dynType_destroy(type);
 }
 
+TEST_F(DynTypeTests, FillSequenceTest) {
+    struct double_sequence {
+        uint32_t cap;
+        uint32_t len;
+        double* buf;
+    };
+
+    dyn_type *type = NULL;
+    int rc = 0;
+    rc = dynType_parseWithStr("[D", NULL, NULL, &type);
+    ASSERT_EQ(0, rc);
+
+    struct double_sequence *seq = NULL;
+    rc = dynType_alloc(type, (void **)&seq);
+    ASSERT_EQ(0, rc);
+    ASSERT_TRUE(seq != NULL);
+
+    rc = dynType_sequence_alloc(type, seq, 1);
+    ASSERT_EQ(0, rc);
+
+    void* loc;
+    rc = dynType_sequence_increaseLengthAndReturnLastLoc(type, seq, (void **)&loc);
+    ASSERT_EQ(0, rc);
+
+    double val = 2.0;
+    dynType_simple_setValue(dynType_sequence_itemType(type), loc, &val);
+    ASSERT_EQ(val, seq->buf[0]);
+
+    rc = dynType_sequence_increaseLengthAndReturnLastLoc(type, seq, (void **)&loc);
+    ASSERT_NE(0, rc);
+    ASSERT_STREQ("Cannot increase sequence length beyond capacity (1)", celix_err_popLastError());
+
+    rc = dynType_sequence_reserve(type, seq, 2);
+    ASSERT_EQ(0, rc);
+    rc = dynType_sequence_locForIndex(type, seq, 1, (void **)&loc);
+    ASSERT_NE(0, rc);
+    ASSERT_STREQ("Requesting index (1) outsize defined length (1) but within capacity", celix_err_popLastError());
+
+
+    rc = dynType_sequence_locForIndex(type, seq, 2, (void **)&loc);
+    ASSERT_NE(0, rc);
+    ASSERT_STREQ("Requested index (2) is greater than capacity (2) of sequence", celix_err_popLastError());
+
+    dynType_free(type, seq);
+    dynType_destroy(type);
+}
+
 TEST_F(DynTypeTests, EnumTest) {
     dyn_type *type = NULL;
     int rc = 0;
diff --git a/libs/dfi/include/dyn_type.h b/libs/dfi/include/dyn_type.h
index 635004b27..7ae474719 100644
--- a/libs/dfi/include/dyn_type.h
+++ b/libs/dfi/include/dyn_type.h
@@ -311,7 +311,7 @@ CELIX_DFI_EXPORT int dynType_sequence_reserve(const dyn_type* type, void* inst,
  * @return 0 if successful.
  * @retval 1 if the index is out of bounds.
  */
-CELIX_DFI_EXPORT int dynType_sequence_locForIndex(const dyn_type* type, void* seqLoc, int index, void** valLoc);
+CELIX_DFI_EXPORT int dynType_sequence_locForIndex(const dyn_type* type, void* seqLoc, uint32_t index, void** valLoc);
 
 /**
  * @brief Increase the length of the sequence by one and return the value location for the last element.
diff --git a/libs/dfi/src/dyn_type.c b/libs/dfi/src/dyn_type.c
index e629900b5..474009205 100644
--- a/libs/dfi/src/dyn_type.c
+++ b/libs/dfi/src/dyn_type.c
@@ -651,9 +651,11 @@ static void dynType_deepFree(const dyn_type* type, void* loc, bool alsoDeleteSel
             case DYN_TYPE_SIMPLE:
                 //nop
                 break;
+//LCOV_EXCL_START
             default:
-                celix_err_pushf("Unexpected switch case. cannot free dyn type %c\n", type->descriptor);
+                assert(0 && "Unexpected switch case. cannot free dyn type");
                 break;
+//LCOV_EXCL_STOP
         }
 
         if (alsoDeleteSelf) {
@@ -666,7 +668,7 @@ static void dynType_freeSequenceType(const dyn_type* type, void* seqLoc) {
     struct generic_sequence* seq = seqLoc;
     const dyn_type* itemType = dynType_sequence_itemType(type);
     void* itemLoc = NULL;
-    int i;
+    uint32_t i;
     for (i = 0; i < seq->len; ++i) {
         dynType_sequence_locForIndex(type, seqLoc, i, &itemLoc);
         dynType_deepFree(itemType, itemLoc, false);
@@ -688,50 +690,39 @@ uint32_t dynType_sequence_length(const void *seqLoc) {
     return seq->len;
 }
 
-int dynType_sequence_locForIndex(const dyn_type* type, void* seqLoc, int index, void** out) {
+int dynType_sequence_locForIndex(const dyn_type* type, void* seqLoc, uint32_t index, void** out) {
     assert(type->type == DYN_TYPE_SEQUENCE);
-    int status = OK;
-
     struct generic_sequence* seq = seqLoc;
 
     size_t itemSize = dynType_size(type->sequence.itemType);
 
     if (index >= seq->cap) {
-        status = ERROR;
-        celix_err_pushf("Requested index (%i) is greater than capacity (%u) of sequence", index, seq->cap);
+        celix_err_pushf("Requested index (%u) is greater than capacity (%u) of sequence", index, seq->cap);
+        return ERROR;
     }
 
     if (index >= seq->len) {
-        status = ERROR;
-        celix_err_pushf("Requesting index (%i) outsize defined length (%u) but within capacity", index, seq->len);
+        celix_err_pushf("Requesting index (%u) outsize defined length (%u) but within capacity", index, seq->len);
+        return ERROR;
     }
 
-    if (status == OK) {
-        char* valLoc = seq->buf + (index * itemSize);
-        (*out) = valLoc;
-    }
+    char* valLoc = seq->buf + (index * itemSize);
+    (*out) = valLoc;
 
-    return status;
+    return OK;
 }
 
 int dynType_sequence_increaseLengthAndReturnLastLoc(const dyn_type* type, void* seqLoc, void** valLoc) {
     assert(type->type == DYN_TYPE_SEQUENCE);
-    int status = OK;
     struct generic_sequence* seq = seqLoc;
 
-    int lastIndex = seq->len;
-    if (seq->len < seq->cap) {
-        seq->len += 1;
-    } else {
-        status = ERROR;
+    uint32_t lastIndex = seq->len;
+    if (seq->len >= seq->cap) {
         celix_err_pushf("Cannot increase sequence length beyond capacity (%u)", seq->cap);
+        return ERROR;
     }
-
-    if (status == OK) {
-        status = dynType_sequence_locForIndex(type, seqLoc, lastIndex, valLoc);
-    }
-
-    return status;
+    seq->len += 1;
+    return dynType_sequence_locForIndex(type, seqLoc, lastIndex, valLoc);
 }
 
 const dyn_type* dynType_sequence_itemType(const dyn_type* type) {
diff --git a/libs/dfi/src/json_serializer.c b/libs/dfi/src/json_serializer.c
index 34d4f577b..a98e3ea85 100644
--- a/libs/dfi/src/json_serializer.c
+++ b/libs/dfi/src/json_serializer.c
@@ -437,7 +437,7 @@ static int jsonSerializer_writeSequence(const dyn_type *type, void *input, json_
     const dyn_type *itemType = dynType_sequence_itemType(type);
     uint32_t len = dynType_sequence_length(input);
 
-    int i = 0;
+    uint32_t i = 0;
     void *itemLoc = NULL;
     json_t *item = NULL;
     for (i = 0; i < len; i += 1) {