diff --git a/britney.py b/britney.py
index 3c3a92f..46d90e5 100755
--- a/britney.py
+++ b/britney.py
@@ -1049,7 +1049,7 @@ class Britney:
                 # for the solving packages, update the excuse to add the dependencies
                 for p in packages:
                     if arch not in self.options.break_arches.split():
-                        excuse.add_dep(p)
+                        excuse.add_dep(p, arch)
                     else:
                         excuse.add_break_dep(p, arch)
 
@@ -1601,14 +1601,29 @@ class Britney:
             parts = e.name.split('/')
             for d in e.deps:
                 ok = False
+                # source -> source dependency; both packages must have
+                # valid excuses
                 if d in upgrade_me or d in unconsidered:
                     ok = True
                 # if the excuse is for a binNMU, also consider d/$arch as a
                 # valid excuse
-                if len(parts) == 2:
+                elif len(parts) == 2:
                     bd = '%s/%s' % (d, parts[1])
                     if bd in upgrade_me or bd in unconsidered:
                         ok = True
+                # if the excuse is for a source package, check each of the
+                # architectures on which the excuse lists a dependency on d,
+                # and consider the excuse valid if it is possible on each
+                # architecture
+                else:
+                    arch_ok = True
+                    for arch in e.deps[d]:
+                        bd = '%s/%s' % (d, arch)
+                        if bd not in upgrade_me and bd not in unconsidered:
+                            arch_ok = False
+                            break
+                    if arch_ok:
+                        ok = True
                 if not ok:
                     e.addhtml("Impossible dependency: %s -> %s" % (e.name, d))
         self.invalidate_excuses(upgrade_me, unconsidered)
diff --git a/excuse.py b/excuse.py
index c750547..f5021d8 100644
--- a/excuse.py
+++ b/excuse.py
@@ -53,7 +53,7 @@ class Excuse:
         self.dontinvalidate = 0
 
         self.invalid_deps = []
-        self.deps = []
+        self.deps = {}
         self.sane_deps = []
         self.break_deps = []
         self.unsat_deps = {}
@@ -85,9 +85,10 @@ class Excuse:
         """Set the urgency of upload of the package"""
         self.urgency = date
 
-    def add_dep(self, name):
+    def add_dep(self, name, arch):
         """Add a dependency"""
-        if name not in self.deps: self.deps.append(name)
+        if name not in self.deps: self.deps[name]=[]
+        self.deps[name].append(arch)
 
     def add_sane_dep(self, name):
         """Add a sane dependency"""