diff --git a/docs/libcurl/opts/CURLOPT_CAINFO_BLOB.3 b/docs/libcurl/opts/CURLOPT_CAINFO_BLOB.3
index ebb27111b9..d3e26d3d05 100644
--- a/docs/libcurl/opts/CURLOPT_CAINFO_BLOB.3
+++ b/docs/libcurl/opts/CURLOPT_CAINFO_BLOB.3
@@ -37,6 +37,10 @@ Pass a pointer to a curl_blob structure, which contains information (pointer
 and size) about a memory block with binary data of PEM encoded content holding
 one or more certificates to verify the HTTPS server with.
 
+If the blob is initialized with the flags member of struct curl_blob set to
+CURL_BLOB_COPY, the application does not have to keep the buffer around after
+setting this.
+
 If \fICURLOPT_SSL_VERIFYPEER(3)\fP is zero and you avoid verifying the
 server's certificate, \fICURLOPT_CAINFO_BLOB(3)\fP is not needed.
 
diff --git a/docs/libcurl/opts/CURLOPT_PROXY_CAINFO_BLOB.3 b/docs/libcurl/opts/CURLOPT_PROXY_CAINFO_BLOB.3
index b2e8be0371..5c8f2443bf 100644
--- a/docs/libcurl/opts/CURLOPT_PROXY_CAINFO_BLOB.3
+++ b/docs/libcurl/opts/CURLOPT_PROXY_CAINFO_BLOB.3
@@ -39,6 +39,10 @@ Pass a pointer to a curl_blob structure, which contains information (pointer
 and size) about a memory block with binary data of PEM encoded content holding
 one or more certificates to verify the HTTPS proxy with.
 
+If the blob is initialized with the flags member of struct curl_blob set to
+CURL_BLOB_COPY, the application does not have to keep the buffer around after
+setting this.
+
 If \fICURLOPT_PROXY_SSL_VERIFYPEER(3)\fP is zero and you avoid verifying the
 server's certificate, \fICURLOPT_PROXY_CAINFO_BLOB(3)\fP is not needed.