diff --git a/winpr/libwinpr/sspi/Negotiate/negotiate.c b/winpr/libwinpr/sspi/Negotiate/negotiate.c
index c2e5b08b1..901cf4376 100644
--- a/winpr/libwinpr/sspi/Negotiate/negotiate.c
+++ b/winpr/libwinpr/sspi/Negotiate/negotiate.c
@@ -477,13 +477,13 @@ cleanup:
 
 static BOOL negotiate_read_neg_token(PSecBuffer input, NegToken* token)
 {
-	WinPrAsn1Decoder dec;
-	WinPrAsn1Decoder dec2;
-	WinPrAsn1_OID oid;
+	WinPrAsn1Decoder dec = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1Decoder dec2 = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1_OID oid = { 0 };
 	WinPrAsn1_tagId contextual = 0;
 	WinPrAsn1_tag tag = 0;
 	size_t len = 0;
-	WinPrAsn1_OctetString octet_string;
+	WinPrAsn1_OctetString octet_string = { 0 };
 	BOOL err = 0;
 
 	WINPR_ASSERT(input);
@@ -990,8 +990,8 @@ static SECURITY_STATUS SEC_ENTRY negotiate_InitializeSecurityContextA(
 
 static const Mech* guessMech(PSecBuffer input_buffer, BOOL* spNego, WinPrAsn1_OID* oid)
 {
-	WinPrAsn1Decoder decoder;
-	WinPrAsn1Decoder appDecoder;
+	WinPrAsn1Decoder decoder = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1Decoder appDecoder = { .encoding = WINPR_ASN1_BER, { 0 } };
 	WinPrAsn1_tagId tag = 0;
 	const char ssp[] = "NTLMSSP";
 
@@ -1039,8 +1039,8 @@ static SECURITY_STATUS SEC_ENTRY negotiate_AcceptSecurityContext(
 	SecBufferDesc mech_input = { SECBUFFER_VERSION, 1, &input_token.mechToken };
 	SecBufferDesc mech_output = { SECBUFFER_VERSION, 1, &output_token.mechToken };
 	SECURITY_STATUS status = SEC_E_INTERNAL_ERROR;
-	WinPrAsn1Decoder dec;
-	WinPrAsn1Decoder dec2;
+	WinPrAsn1Decoder dec = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1Decoder dec2 = { .encoding = WINPR_ASN1_BER, { 0 } };
 	WinPrAsn1_tagId tag = 0;
 	WinPrAsn1_OID oid = { 0 };
 	const Mech* first_mech = NULL;
diff --git a/winpr/libwinpr/sspi/sspi_gss.c b/winpr/libwinpr/sspi/sspi_gss.c
index 26c3927dc..9fc9340c2 100644
--- a/winpr/libwinpr/sspi/sspi_gss.c
+++ b/winpr/libwinpr/sspi/sspi_gss.c
@@ -86,8 +86,8 @@ cleanup:
 BOOL sspi_gss_unwrap_token(const SecBuffer* buf, WinPrAsn1_OID* oid, uint16_t* tok_id,
                            sspi_gss_data* token)
 {
-	WinPrAsn1Decoder dec;
-	WinPrAsn1Decoder dec2;
+	WinPrAsn1Decoder dec = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1Decoder dec2 = { .encoding = WINPR_ASN1_BER, { 0 } };
 	WinPrAsn1_tagId tag = 0;
 	wStream sbuffer = { 0 };
 	wStream* s = NULL;
diff --git a/winpr/libwinpr/utils/asn1/asn1.c b/winpr/libwinpr/utils/asn1/asn1.c
index c91484bac..e8b503d1b 100644
--- a/winpr/libwinpr/utils/asn1/asn1.c
+++ b/winpr/libwinpr/utils/asn1/asn1.c
@@ -1388,7 +1388,7 @@ size_t WinPrAsn1DecReadContextualBool(WinPrAsn1Decoder* dec, WinPrAsn1_tagId tag
 {
 	size_t ret = 0;
 	size_t ret2 = 0;
-	WinPrAsn1Decoder content;
+	WinPrAsn1Decoder content = { .encoding = WINPR_ASN1_BER, { 0 } };
 
 	ret = readContextualHeader(dec, tagId, error, &content);
 	if (!ret)
@@ -1410,7 +1410,7 @@ size_t WinPrAsn1DecReadContextualInteger(WinPrAsn1Decoder* dec, WinPrAsn1_tagId
 {
 	size_t ret = 0;
 	size_t ret2 = 0;
-	WinPrAsn1Decoder content;
+	WinPrAsn1Decoder content = { .encoding = WINPR_ASN1_BER, { 0 } };
 
 	ret = readContextualHeader(dec, tagId, error, &content);
 	if (!ret)
@@ -1432,7 +1432,7 @@ size_t WinPrAsn1DecReadContextualOID(WinPrAsn1Decoder* dec, WinPrAsn1_tagId tagI
 {
 	size_t ret = 0;
 	size_t ret2 = 0;
-	WinPrAsn1Decoder content;
+	WinPrAsn1Decoder content = { .encoding = WINPR_ASN1_BER, { 0 } };
 
 	ret = readContextualHeader(dec, tagId, error, &content);
 	if (!ret)
@@ -1455,7 +1455,7 @@ size_t WinPrAsn1DecReadContextualOctetString(WinPrAsn1Decoder* dec, WinPrAsn1_ta
 {
 	size_t ret = 0;
 	size_t ret2 = 0;
-	WinPrAsn1Decoder content;
+	WinPrAsn1Decoder content = { .encoding = WINPR_ASN1_BER, { 0 } };
 
 	ret = readContextualHeader(dec, tagId, error, &content);
 	if (!ret)
@@ -1477,7 +1477,7 @@ size_t WinPrAsn1DecReadContextualSequence(WinPrAsn1Decoder* dec, WinPrAsn1_tagId
 {
 	size_t ret = 0;
 	size_t ret2 = 0;
-	WinPrAsn1Decoder content;
+	WinPrAsn1Decoder content = { .encoding = WINPR_ASN1_BER, { 0 } };
 
 	ret = readContextualHeader(dec, tagId, error, &content);
 	if (!ret)
diff --git a/winpr/libwinpr/utils/test/TestASN1.c b/winpr/libwinpr/utils/test/TestASN1.c
index 99d9e5db2..79d5b82b3 100644
--- a/winpr/libwinpr/utils/test/TestASN1.c
+++ b/winpr/libwinpr/utils/test/TestASN1.c
@@ -30,14 +30,14 @@ static const BYTE utctimeContent[] = { 0x17, 0x0D, 0x32, 0x31, 0x30, 0x33, 0x31,
 
 int TestASN1Read(int argc, char* argv[])
 {
-	WinPrAsn1Decoder decoder;
-	WinPrAsn1Decoder seqDecoder;
-	wStream staticS;
+	WinPrAsn1Decoder decoder = { .encoding = WINPR_ASN1_BER, { 0 } };
+	WinPrAsn1Decoder seqDecoder = { .encoding = WINPR_ASN1_BER, { 0 } };
+	wStream staticS = { 0 };
 	WinPrAsn1_BOOL boolV = 0;
 	WinPrAsn1_INTEGER integerV = 0;
-	WinPrAsn1_OID oidV;
+	WinPrAsn1_OID oidV = { 0 };
 	WinPrAsn1_IA5STRING ia5stringV = NULL;
-	WinPrAsn1_UTCTIME utctimeV;
+	WinPrAsn1_UTCTIME utctimeV = { 0 };
 	WinPrAsn1_tag tag = 0;
 	size_t len = 0;
 	BOOL error = 0;