diff --git a/src/mapper/collector.py b/src/mapper/collector.py
index 2dfc8d554846db139523b8b4e7798e47945899eb..da0fbd594785dc5a144230b566158d008b58e560 100644
--- a/src/mapper/collector.py
+++ b/src/mapper/collector.py
@@ -11,6 +11,10 @@ class TermCollector(IdentityMapper):
     def __init__(self, parameters=set()):
         self.parameters = parameters
 
+    def get_dependencies(self, expr):
+        from pymbolic.mapper.dependency import DependencyMapper
+        return DependencyMapper()(expr)
+
     def split_term(self, mul_term):
         """Returns  a pair consisting of:
         - a frozenset of (base, exponent) pairs
@@ -20,7 +24,6 @@ class TermCollector(IdentityMapper):
 
         The argument `product' has to be fully expanded already.
         """
-        from pymbolic import get_dependencies, is_constant
         from pymbolic.primitives import Product, Power, AlgebraicLeaf
 
         def base(term):
@@ -39,7 +42,7 @@ class TermCollector(IdentityMapper):
             terms = mul_term.children
         elif isinstance(mul_term, (Power, AlgebraicLeaf)):
             terms = [mul_term]
-        elif is_constant(mul_term):
+        elif not bool(self.get_dependencies(mul_term)):
             terms = [mul_term]
         else:
             raise RuntimeError, "split_term expects a multiplicative term"
@@ -58,7 +61,7 @@ class TermCollector(IdentityMapper):
         cleaned_base2exp = {}
         for base, exp in base2exp.iteritems():
             term = base**exp
-            if  get_dependencies(term) <= self.parameters:
+            if  self.get_dependencies(term) <= self.parameters:
                 coefficients.append(term)
             else:
                 cleaned_base2exp[base] = exp