diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ebb969998c..f3a2175dc9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-11-29  Tom Tromey  <tom@tromey.com>
+
+	* symfile.c (add_symbol_file_command): Error if some arguments to
+	-s are missing.  Change unrecognized-argument error message.
+	(_initialize_symfile): Fix usage text for add-symbol-file.
+
 2017-11-27  Tom Tromey  <tom@tromey.com>
 
 	* Makefile.in (REMOTE_OBS): Remove.
diff --git a/gdb/symfile.c b/gdb/symfile.c
index feb50f8b79..c19cdd20eb 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2244,8 +2244,7 @@ add_symbol_file_command (const char *args, int from_tty)
 	      expecting_sec_addr = 1;
 	    }
 	  else
-	    error (_("USAGE: add-symbol-file <filename> <textaddress>"
-		     " [-readnow] [-s <secname> <addr>]*"));
+	    error (_("Unrecognized argument \"%s\""), arg);
 	}
     }
 
@@ -2257,6 +2256,11 @@ add_symbol_file_command (const char *args, int from_tty)
     error (_("The address where %s has been loaded is missing"),
 	   filename.get ());
 
+  if (expecting_sec_name)
+    error (_("Missing section name after \"-s\""));
+  else if (expecting_sec_addr)
+    error (_("Missing section address after \"-s\""));
+
   /* Print the prompt for the query below.  And save the arguments into
      a sect_addr_info structure to be passed around to other
      functions.  We have to split this up into separate print
@@ -3882,11 +3886,11 @@ to execute."), &cmdlist);
 
   c = add_cmd ("add-symbol-file", class_files, add_symbol_file_command, _("\
 Load symbols from FILE, assuming FILE has been dynamically loaded.\n\
-Usage: add-symbol-file FILE ADDR [-s <SECT> <SECT_ADDR> -s <SECT> <SECT_ADDR>\
- ...]\nADDR is the starting address of the file's text.\n\
-The optional arguments are section-name section-address pairs and\n\
+Usage: add-symbol-file FILE ADDR [-readnow | -s SECT-NAME SECT-ADDR]...\n\
+ADDR is the starting address of the file's text.\n\
+Each '-s' argument provides a section name and address, and\n\
 should be specified if the data and bss segments are not contiguous\n\
-with the text.  SECT is a section name to be loaded at SECT_ADDR."),
+with the text.  SECT-NAME is a section name to be loaded at SECT-ADDR."),
 	       &cmdlist);
   set_cmd_completer (c, filename_completer);
 
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 87b917e0c5..4fba24bedc 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-29  Tom Tromey  <tom@tromey.com>
+
+	* gdb.base/relocate.exp: Update invalid argument test.
+	Add new tests for invalid arguments.
+
 2017-11-29  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
 	* gdb.cp/psymtab-parameter.cc (func): Change return type back to long.
diff --git a/gdb/testsuite/gdb.base/relocate.exp b/gdb/testsuite/gdb.base/relocate.exp
index 5639cc8847..6eef15fb20 100644
--- a/gdb/testsuite/gdb.base/relocate.exp
+++ b/gdb/testsuite/gdb.base/relocate.exp
@@ -31,11 +31,19 @@ gdb_reinitialize_dir $srcdir/$subdir
 
 #Check that invalid options are rejected.
 foreach x {"-raednow" "readnow" "foo" "-readnow s"} {
+    set word [lindex $x [expr [llength $x]-1]]
     gdb_test "add-symbol-file ${binfile} 0 $x" \
-	"USAGE: add-symbol-file <filename> <textaddress>.*-readnow.*-s <secname> <addr>.*" \
-	"add-symbol-file: unknown option $x"
+	"Unrecognized argument \"$word\"" \
+	"add-symbol-file: unknown option $word"
 }
 
+gdb_test "add-symbol-file ${binfile} 0 -s" \
+    "Missing section name after .-s." \
+    "add-symbol-file bare -s"
+gdb_test "add-symbol-file ${binfile} 0 -s .whatever" \
+    "Missing section address after .-s." \
+    "add-symbol-file missing address"
+
 # Load the object file.
 gdb_test "add-symbol-file ${binfile} 0" \
 	"Reading symbols from .*${testfile}\\.o\\.\\.\\.done\\.(|\r\nUsing host libthread_db library .*libthread_db.so.*\\.)" \