--- a/src/paml.h
+++ b/src/paml.h
@@ -372,9 +372,9 @@
 void printSptree(void);
 
 
-enum {BASEseq=0, CODONseq, AAseq, CODON2AAseq, BINARYseq, BASE5seq} SeqTypes;
+typedef enum {BASEseq=0, CODONseq, AAseq, CODON2AAseq, BINARYseq, BASE5seq} SeqTypes;
 
-enum {PrBranch=1, PrNodeNum=2, PrLabel=4, PrNodeStr=8, PrAge=16, PrOmega=32} OutTreeOptions;
+typedef enum {PrBranch=1, PrNodeNum=2, PrLabel=4, PrNodeStr=8, PrAge=16, PrOmega=32} OutTreeOptions;
 
 
 /* use mean (0; default) for discrete gamma instead of median (1) */