diff --git a/src/httpfetch.cpp b/src/httpfetch.cpp
index 13daaefb6..18c0bc131 100644
--- a/src/httpfetch.cpp
+++ b/src/httpfetch.cpp
@@ -300,12 +300,14 @@ HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
 			break;
 		}
 		if (request.method != HTTP_GET) {
-			if (!request.raw_data.empty()) {
+			if (request.fields.empty()) {
+				// Note that we need to set this to an empty buffer (not NULL)
+				// even if no data is to be sent.
 				curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 						request.raw_data.size());
 				curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 						request.raw_data.c_str());
-			} else if (!request.fields.empty()) {
+			} else {
 				std::string str;
 				for (auto &field : request.fields) {
 					if (!str.empty())
@@ -314,10 +316,8 @@ HTTPFetchOngoing::HTTPFetchOngoing(const HTTPFetchRequest &request_,
 					str += "=";
 					str += urlencode(field.second);
 				}
-				curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
-						str.size());
-				curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
-						str.c_str());
+				curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, str.size());
+				curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS, str.c_str());
 			}
 		}
 	}
diff --git a/src/httpfetch.h b/src/httpfetch.h
index a04b969df..f0c622775 100644
--- a/src/httpfetch.h
+++ b/src/httpfetch.h
@@ -65,7 +65,7 @@ struct HTTPFetchRequest
 	// Fields of the request
 	StringMap fields;
 
-	// Raw data of the request overrides fields
+	// Raw data of the request (instead of fields)
 	std::string raw_data;
 
 	// If not empty, should contain entries such as "Accept: text/html"