diff --git a/dlls/secur32/ntlm.c b/dlls/secur32/ntlm.c
index 86d61cff3c0..853edd10bb0 100644
--- a/dlls/secur32/ntlm.c
+++ b/dlls/secur32/ntlm.c
@@ -1634,7 +1634,7 @@ static SECURITY_STATUS SEC_ENTRY ntlm_DecryptMessage(PCtxtHandle phContext,
     return ret;
 }
 
-static SecurityFunctionTableA ntlmTableA = {
+static const SecurityFunctionTableA ntlmTableA = {
     1,
     NULL,   /* EnumerateSecurityPackagesA */
     ntlm_QueryCredentialsAttributesA,   /* QueryCredentialsAttributesA */
@@ -1665,7 +1665,7 @@ static SecurityFunctionTableA ntlmTableA = {
     NULL,   /* SetContextAttributesA */
 };
 
-static SecurityFunctionTableW ntlmTableW = {
+static const SecurityFunctionTableW ntlmTableW = {
     1,
     NULL,   /* EnumerateSecurityPackagesW */
     ntlm_QueryCredentialsAttributesW,   /* QueryCredentialsAttributesW */
diff --git a/dlls/secur32/schannel.c b/dlls/secur32/schannel.c
index b4c1d57fb8e..a8f50b6f647 100644
--- a/dlls/secur32/schannel.c
+++ b/dlls/secur32/schannel.c
@@ -290,7 +290,7 @@ static SECURITY_STATUS SEC_ENTRY schan_InitializeSecurityContextW(
     return ret;
 }
 
-static SecurityFunctionTableA schanTableA = {
+static const SecurityFunctionTableA schanTableA = {
     1,
     NULL, /* EnumerateSecurityPackagesA */
     schan_QueryCredentialsAttributesA,
@@ -321,7 +321,7 @@ static SecurityFunctionTableA schanTableA = {
     NULL, /* SetContextAttributesA */
 };
 
-static SecurityFunctionTableW schanTableW = {
+static const SecurityFunctionTableW schanTableW = {
     1,
     NULL, /* EnumerateSecurityPackagesW */
     schan_QueryCredentialsAttributesW,