diff --git a/gnuplot.spec b/gnuplot.spec
index 7a678cd..4386456 100644
--- a/gnuplot.spec
+++ b/gnuplot.spec
@@ -72,6 +72,7 @@ BuildRequires:  tex(booktabs.sty)
 BuildRequires:  tex(fancyhdr.sty)
 BuildRequires:  tex(gttn1000.tfm)
 BuildRequires:  tex(hyperref.sty)
+BuildRequires:  tex(imakeidx.sty)
 BuildRequires:  tex(lgrcmr.fd)
 BuildRequires:  tex(pdftex.def)
 BuildRequires:  tex(subfigure.sty)