diff --git src/interfaces/libpq/fe-exec.c src/interfaces/libpq/fe-exec.c
index d572bde..99bab2c 100644
--- src/interfaces/libpq/fe-exec.c
+++ src/interfaces/libpq/fe-exec.c
@@ -1855,8 +1855,15 @@ PQsendQueryGuts(PGconn *conn,
 			}
 			else
 			{
-				/* text parameter, do not use paramLengths */
-				nbytes = strlen(paramValues[i]);
+				/* text parameter */
+				if (paramLengths && paramLengths[i] >= 0)
+				{
+					nbytes = paramLengths[i];  // use supplied length
+				}
+				else
+				{
+					nbytes = strlen(paramValues[i]);  // fallback to strlen
+				}
 			}
 			if (pqPutInt(nbytes, 4, conn) < 0 ||
 				pqPutnchar(paramValues[i], nbytes, conn) < 0)