diff --git a/crypto/cms/cms_lib.c b/crypto/cms/cms_lib.c
index f9c73d1cbf4e88748175958803e0e99aaf4756fa..86d92996c64c39919741fe054fe2f94d7be3efa3 100644
--- a/crypto/cms/cms_lib.c
+++ b/crypto/cms/cms_lib.c
@@ -19,7 +19,7 @@
 IMPLEMENT_ASN1_FUNCTIONS(CMS_ContentInfo)
 IMPLEMENT_ASN1_PRINT_FUNCTION(CMS_ContentInfo)
 
-const ASN1_OBJECT *CMS_get0_type(CMS_ContentInfo *cms)
+const ASN1_OBJECT *CMS_get0_type(const CMS_ContentInfo *cms)
 {
     return cms->contentType;
 }
diff --git a/doc/crypto/CMS_get0_type.pod b/doc/crypto/CMS_get0_type.pod
index 06b06551be0b4a54d248956efa5cd49169b88af3..cad8d3f66280f68bed197d8c69bcd10196e35cf1 100644
--- a/doc/crypto/CMS_get0_type.pod
+++ b/doc/crypto/CMS_get0_type.pod
@@ -8,7 +8,7 @@ CMS_get0_type, CMS_set1_eContentType, CMS_get0_eContentType, CMS_get0_content -
 
  #include <openssl/cms.h>
 
- const ASN1_OBJECT *CMS_get0_type(CMS_ContentInfo *cms);
+ const ASN1_OBJECT *CMS_get0_type(const CMS_ContentInfo *cms);
  int CMS_set1_eContentType(CMS_ContentInfo *cms, const ASN1_OBJECT *oid);
  const ASN1_OBJECT *CMS_get0_eContentType(CMS_ContentInfo *cms);
  ASN1_OCTET_STRING **CMS_get0_content(CMS_ContentInfo *cms);
diff --git a/include/openssl/cms.h b/include/openssl/cms.h
index 57c877de9869a3578e7100812fc9766fa8104342..b1252acd6e18b5d6f850777f3b1cb765669cd84b 100644
--- a/include/openssl/cms.h
+++ b/include/openssl/cms.h
@@ -73,7 +73,7 @@ DECLARE_ASN1_PRINT_FUNCTION(CMS_ContentInfo)
 # define CMS_KEY_PARAM                   0x40000
 # define CMS_ASCIICRLF                   0x80000
 
-const ASN1_OBJECT *CMS_get0_type(CMS_ContentInfo *cms);
+const ASN1_OBJECT *CMS_get0_type(const CMS_ContentInfo *cms);
 
 BIO *CMS_dataInit(CMS_ContentInfo *cms, BIO *icont);
 int CMS_dataFinal(CMS_ContentInfo *cms, BIO *bio);