diff --git a/interfaces/cython/cantera/ck2yaml.py b/interfaces/cython/cantera/ck2yaml.py
index 55b9d90bd9..109fa875b4 100644
--- a/interfaces/cython/cantera/ck2yaml.py
+++ b/interfaces/cython/cantera/ck2yaml.py
@@ -886,15 +886,18 @@ def read_NASA7_entry(self, lines, TintDefault, comments):
         if not composition:
             raise InputError("Error parsing elemental composition for "
                              "species '{}'", species)
-        else:
-            for symbol in composition.keys():
-
-                # check if self.parse_composition parses composition correctly
-                if any(map(str.isdigit, symbol)) and symbol not in self.elements:
-                    raise InputError("Error parsing elemental composition for "
-                                     "species thermo entry\n{}"
-                                     "\n the first line has an incorrect format", "".join(lines))
-                                     
+
+        for symbol in composition.keys():
+            # Some CHEMKIN input files may have quantities of elements with
+            # more than 3 digits. This violates the column-based input format
+            # standard, so the entry cannot be read and we need to raise a
+            # more useful error message.
+            if any(map(str.isdigit, symbol)) and symbol not in self.elements:
+                raise InputError("Error parsing elemental composition for "
+                                 "species thermo entry:\n{}\nElement amounts"
+                                 "can have no more than 3 digits",
+                                 "".join(lines))
+
         # Extract the NASA polynomial coefficients
         # Remember that the high-T polynomial comes first!
         Tmin = fortFloat(lines[0][45:55])
diff --git a/test/data/big_element_num_err.inp b/test/data/big_element_num_err.inp
index 7517792a61..d9474de802 100644
--- a/test/data/big_element_num_err.inp
+++ b/test/data/big_element_num_err.inp
@@ -15,8 +15,8 @@ BIN6BJ
 END
 
 THERMO ALL
-    270.000   1000.000   3500.000 
-BIN7AJ                 C 1250H 812          G    300.00   3500.00 1260.00      1 
+    270.000   1000.000   3500.000
+BIN7AJ                 C 1250H 812          G    300.00   3500.00 1260.00      1
  2.35938249e+03 3.50442304e+00-1.25852280e-03 2.00397985e-07-1.15957197e-11    2
  2.45225502e+05-1.29759728e+04-1.05686227e+03 1.43496445e+01-1.41695007e-02    3
  7.03160324e-06-1.36699359e-09 1.10611918e+06 4.29496756e+03                   4
@@ -36,12 +36,12 @@ CO                      C   1O   1          G    200.00   3500.00  960.00      1
 -1.41723335e+04 7.41443560e+00 3.75723891e+00-2.14465241e-03 5.42079005e-06    3
 -4.17025963e-09 1.11901127e-12-1.43575530e+04 2.79976799e+00                   4
 
-BIN6AJ                  C 640H 43           G    300.00   3500.00 1290.00      1 
+BIN6AJ                  C 640H 43           G    300.00   3500.00 1290.00      1
  1.23762821e+03 1.77026241e+00-6.22545371e-04 9.54207658e-08-5.13173999e-12    2
  1.25536835e+05-6.67884001e+03-5.26755261e+02 7.24121890e+00-6.98412269e-03    3
  3.38305762e-06-6.42270665e-10 5.80747770e+05 2.28257683e+03                   4
 
-BIN6BJ                  C 640H 127          G    300.00   3500.00 1390.00      1 
+BIN6BJ                  C 640H 127          G    300.00   3500.00 1390.00      1
  1.08992363e+03 1.08035536e+00-3.02579890e-04 2.55048499e-08 8.09218683e-13    2
 -2.94595285e+05-5.83854863e+03-5.54531539e+02 5.81260044e+00-5.40931919e-03    3
  2.47478029e-06-4.39707947e-10 1.62563251e+05 2.63652221e+03                   4