diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 360d9a45476..a5055271ae3 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3493,11 +3493,17 @@ keep_going:						/* We will come back to here until there is
 					}
 					if (SSLok == 'S')
 					{
+						if (conn->Pfdebug)
+							pqTraceOutputCharResponse(conn, "SSLResponse",
+													  SSLok);
 						/* mark byte consumed */
 						conn->inStart = conn->inCursor;
 					}
 					else if (SSLok == 'N')
 					{
+						if (conn->Pfdebug)
+							pqTraceOutputCharResponse(conn, "SSLResponse",
+													  SSLok);
 						/* mark byte consumed */
 						conn->inStart = conn->inCursor;
 
@@ -3635,6 +3641,10 @@ keep_going:						/* We will come back to here until there is
 
 					if (gss_ok == 'N')
 					{
+						if (conn->Pfdebug)
+							pqTraceOutputCharResponse(conn, "GSSENCResponse",
+													  gss_ok);
+
 						/*
 						 * The connection is still valid, so if it's OK to
 						 * continue without GSS, we can proceed using this
@@ -3648,6 +3658,10 @@ keep_going:						/* We will come back to here until there is
 												gss_ok);
 						goto error_return;
 					}
+
+					if (conn->Pfdebug)
+						pqTraceOutputCharResponse(conn, "GSSENCResponse",
+												  gss_ok);
 				}
 
 				/* Begin or continue GSSAPI negotiation */
diff --git a/src/interfaces/libpq/fe-trace.c b/src/interfaces/libpq/fe-trace.c
index 367b322b992..3527b9f0f5d 100644
--- a/src/interfaces/libpq/fe-trace.c
+++ b/src/interfaces/libpq/fe-trace.c
@@ -840,3 +840,23 @@ pqTraceOutputNoTypeByteMessage(PGconn *conn, const char *message)
 
 	fputc('\n', conn->Pfdebug);
 }
+
+/*
+ * Trace a single-byte backend response received for a known request
+ * type the frontend previously sent.  Only useful for the simplest of
+ * FE/BE interaction workflows such as SSL/GSS encryption requests.
+ */
+void
+pqTraceOutputCharResponse(PGconn *conn, const char *responseType,
+						  char response)
+{
+	if ((conn->traceFlags & PQTRACE_SUPPRESS_TIMESTAMPS) == 0)
+	{
+		char		timestr[128];
+
+		pqTraceFormatTimestamp(timestr, sizeof(timestr));
+		fprintf(conn->Pfdebug, "%s\t", timestr);
+	}
+
+	fprintf(conn->Pfdebug, "B\t1\t%s\t %c\n", responseType, response);
+}
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 03e4da40ba1..d97b595c97f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -889,6 +889,8 @@ extern ssize_t pg_GSS_read(PGconn *conn, void *ptr, size_t len);
 extern void pqTraceOutputMessage(PGconn *conn, const char *message,
 								 bool toServer);
 extern void pqTraceOutputNoTypeByteMessage(PGconn *conn, const char *message);
+extern void pqTraceOutputCharResponse(PGconn *conn, const char *responseType,
+									  char response);
 
 /* === miscellaneous macros === */