diff --git a/R/sigma.R b/R/sigma.R
index 332666a..750bcfd 100644
--- a/R/sigma.R
+++ b/R/sigma.R
@@ -16,7 +16,7 @@
 #'
 #' @return
 #'  A named list with two elements: "time" and "freq", in time and frequency
-#'  units. They obey the property \eqn{time \times freq = \frac{8]{\pi}}}.
+#'  units. They obey the property \eqn{time \times freq = \frac{8}{\pi}}.
 #'
 #' @examples
 #' sigma_res(1, u(440, "Hz"))
diff --git a/man/sigma_res.Rd b/man/sigma_res.Rd
index eafbb32..3bc26f1 100644
--- a/man/sigma_res.Rd
+++ b/man/sigma_res.Rd
@@ -14,7 +14,7 @@ calculated. Must be a quantity with frequency units (see \code{\link[=u]{u()}}).
 }
 \value{
 A named list with two elements: "time" and "freq", in time and frequency
-units. They obey the property \eqn{time \times freq = \frac{8]{\pi}}}.
+units. They obey the property \eqn{time \times freq = \frac{8}{\pi}}.
 }
 \description{
 For a given \code{sigma} and reference frequency \code{freq} this function calculates